The invention relates to a combined high pressure cleaning and suction appliance incorporating a drive motor whose drive shaft drives both a high pressure pump and a suction fan.
Such a combined high pressure cleaning appliance is known from DE 3728287 C2 for example. Provision is made therein for the suction turbine and the high pressure pump to form a modular unit, this being connected, when in operation, to the drive motor used for driving both the high pressure pump and the suction fan, accordingly, the drive motor must be designed to be sufficiently large and powerful.
The object of the invention is to design a combined high pressure cleaning and suction appliance of the above type in such a manner that it becomes possible to drive the arrangement with a less powerful and consequently smaller drive motor.
In accordance with the invention, this object is achieved in the case of a combined high pressure cleaning and suction appliance as described hereinabove in that the drive shaft of the drive motor is connected to the high pressure pump and to the suction fan via a respective coupling, and in that there are provided switching means which, on each occasion, selectively close one of the two couplings and open the other one.
The consequence of such a design is that the drive motor drives just the high pressure pump or just the suction fan at any one time so that the motor can be designed for operating just one of these two devices. Nevertheless, the user is able to select which of the two devices should be driven at any one time, by the motor, by actuating the switching means.
The couplings may be normal rotational couplings such as those readily known to the skilled person. The couplings may, for example, be actuated electromagnetically, hydraulically or pneumatically.
The matter of basic importance is that the actuation should always be such that there can only be one effective rotational connection between the motor and one of the two devices, whilst the connection to the respective other device is then open.
In a particularly preferred embodiment, provision is made for the couplings to be in the form of free-wheel couplings which permit rotational coupling to occur in only one direction of rotation, for the two free-wheel couplings to have opposed directions of permitted rotational coupling, and for the switching means for selectively opening and closing the couplings to be means for reversing the direction of rotation of the drive shaft of the drive motor.
By virtue of such a design, one can obtain a particularly simple form of construction since, in this construction, it is merely necessary to reverse the direction of rotation of the drive shaft of the motor so as to selectively close one or the other of the couplings. The couplings then only drive their respective devices when the drive shaft is rotating in a certain direction, whereas the drive is not taken up in the opposite direction and the coupling free-wheels.
It is propitious for the drive motor, the couplings, the high pressure pump and the suction fan to be arranged so as to be mutually co-axial.
In particular, provision may be made for one coupling and the high pressure pump to be arranged at one end of the drive motor, whilst the other coupling and the suction fan are arranged at the opposite end thereof.
It is propitious for the drive shaft to be disposed vertically in the appliance, whereupon all of the other devices should then be accommodated as a tower-like arrangement in the appliance.
In a modified embodiment, the drive shaft may be disposed horizontally in the appliance, whereupon the other devices would then be arranged side-by-side.
A gearing may be inserted between the coupling for the high pressure pump and the high pressure pump itself, and the same applies for the coupling for the suction fan and the suction fan.